Nick Christenson is an independent consultant with expertise in open source, information security and risk management, and Internet services. His specialty is in bottom-up deployment of scalable Internet services. Among other organizations, he has worked at the Jet Propulsion Laboratory, EarthLink Network, and Sendmail. Mr. Christenson has written numerous papers and articles, mostly focusing on the deployment of scalable Internet services, and is the author of the booksendmail Performance Tuning. He can be reached at npc at acm.org.